Information concerning the neurobiological features of developmental language disorder has the potential to provide an anchor for understanding the neural bases, presenting behavioral signs, and prognosis of this disorder. However, little is currently known of the relations among the neuroanatomical, neurophysiological, and behavioral components of the disorder. This proposal addresses this need through two sets of studies. The first is a longitudinal study of children with developmental language disorder from ages 5 to 9 years, and of their families during this time. The behavioral profiles of the family members over this period will be related to their neuroanatomical status, as reflected by MRI analyses performed during years 04 and 05 of the project. Study of the probands in these families will explore the relation between the behavioral signs of developmental language disorder that emerge with time and selected components of the neuroanatomical profile of these children. This will provide insights into the relative predictive value of the behavioral and neuroanatomical signs of the disorder. Study of the first degree relatives (parents and siblings) will provide insight into the degree of variability across generations (probands compared with parents) and with generations (probands compared with siblings at equivalent ages across time). This will provide an index of the range that can be attributed to a relatively similar biological background. The longitudinal behavioral data will provide practical information on test-score stability in this population and on the relations between early test-scores and later behavioral- status. A second set of three studies integrates neurophysiological information with neuroanatomical and behavioral data in adults with developmental language disorder. Adult subjects represent the developmental "end point" of the disorder and their residual deficits reflect the set of behaviors that are fundamental to the longterm nature of the disorder. Among these are deficits in semantic comprehension. Three studies explore components of semantic processing in adults with developmental language disorder with electrophysiologic techniques. These studies relate neurophysiological correlates of linguistic and nonlinguistic processing (i.e., N40O waveforms effects) to subjects neuroanatomical and behavioral status. In combination, the proposed studies will provide an integrated view of how the neuroanatomy and neurophysiology of this disorder relates to its clinical presentation from childhood into adulthood.